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June

This calendar’s monthly planting guidelines are based on USDA zone 9, but they are adaptable to most zones. To find your zone, go to the National Gardening Association’s website. If your zone is 7, 8, or 9, you can safely use this guide. If your zone is 4, 5, or 6, then add a month before beginning your spring tasks and start your fall tasks a month earlier. If your zone is 10 or 11, subtract a month to your spring tasks. Your fall and winter tasks should remain the same as the original guide if you are in zones 10 or 11. These are all general guidelines. Your specific microclimate, which depends on distance to a large body of water (like gigantic lakes or oceans) and elevation, will make your zone fluctuate. Consult your local county extension office to get more detailed zone and planting guide information.

Tasks for June:

  • Mulch
  • Remove leaves that touch ground
  • Make cages; push in leaves
  • Continued maintenance: Spray and check for bugs

Mulch

Tomatoes benefit greatly from being mulched. The word “mulch” means just about anything you put on top of the soil to serve several purposes. Some mulches are better than others, however.

Mulching tomato beds accomplishes these important tasks:

  •  Saves water
  •  Reduces or eliminates weeds
  •  Keeps roots cool in hot temperatures
  •  Replenishes soils
  •  Reduces diseases
  •  Keeps fruit from damage

For tomatoes, plastic, straw, or alfalfa hay mulches are recommended. Other good ones are compost, bark, fallen leaves, and chopped cover crops. There are benefits and detriments to each type of mulch and many more negative issues associated with plain, bare soil. So please mulch your garden beds, someway, somehow. They’ll love you for it.

Plastic was discussed in the March guide (and, yes, this is considered a “mulch” because it lies on top of the soil surface). Clear plastic is preferable because it heats the soil faster in the spring, and tomatoes are yearning for warm soil when first planted. This is why no other mulch should be applied until June, when the weather starts to warm up. Otherwise, if you apply non-plastic mulches earlier than that, when the soil is still cold, you’ll be keeping IN the cold—not something tomatoes desire in the spring.

Clear plastic mulch is the only type of mulch that will totally keep the weeds down. Other mulches help with reducing weeds, but not totally. Plastic will also recycle water better than non-plastic. Your irrigation lines should be beneath the mulch for maximum water saving. The thing that plastic mulch cannot do is replenish soils like straw, alfalfa, or chopped cover crops will. Use UV-rated greenhouse-type plastic; it’s a bit more expensive, but you can buy it by the foot online.

Resist the temptation to buy visqueen-type plastic at the hardware store. If you use that, the sun breaks it down by the end of the season, and you’ll have a million little pieces of plastic blowing around your yard. Greenhouse UV plastic can actually be carefully taken off the beds after the season has ended, stored, and used again the following season.

Be aware, however, that clear plastic will eventually heat the soil too much. This happens around the beginning of July. This a good time to cover any sunlight-exposed plastic with straw. By July, the tomatoes will have leafed out quite a bit and shade the plastic. Anything not shaded should be covered with something to keep the heat down: straw, bark mulch, or other organic matter that will cut the heat. Remember: Warm soil is fantastic in spring and early summer. Extra-hot soil is not good in mid to late summer.

Black plastic is fine, too, but it stays hotter longer in the summer than clear plastic. And clear plastic’s function of helping to solarize the soil from surface diseases is more effective than black plastic. You may have heard of red plastic, which supposedly stimulates reproduction in tomato plants such that they produce more fruit, but this is not proven as fact.

A word on alfalfa hay: Tomatoes just love it. They seem to have a symbiotic relationship with it. And once the season is over, you can dig it into your beds for added organic and nitrogen matter. If you use any organic matter like straw, alfalfa hay, compost, bark, and chopped leaves to mulch with, ensure that you’ve layered it sufficiently thick. It WILL shrink soon after you put it on and continue shrinking. You’ll get no benefit from it if it shrinks and exposes the top of the soil, or even if the covering is thin. You’ll need a good three inches of compost or bark, and four inches of straw or alfalfa or leaves. Good, thick mulches—and also plastic mulches—do a part in keeping diseases down.

Water from rain or hand-irrigating can splash garden soil up onto the tomato leaves, making them more susceptible to disease. Also, any tomatoes that touch the bare soil may quickly become infested with destructive pests like wireworms, earwigs, and pillbugs. This is another reason plastic mulches are so great: They protect the plant from more diseases while protecting the fruit from decay and some pests.

This mulching should be done in early June, after the soil warms up and before the extra-big tomato cages are put into the beds. It’s much easier to mulch when the tomatoes just have their small cages on them.

Remove leaves that touch the ground

As the tomato plant grows, branches and leaves can elongate and droop, allowing leaves to touch the ground. Regardless of whether you’ve mulched or not, it’s best to clean up these leaves. Remove them using clippers. Don’t pull or pinch of leaves with your fingers; you’re bound to tear the stems or branches and damage the tomato plant.

Make cages

By now, you should have either put small conical wire cages on your tomatoes or staked the main stem with a piece of bamboo. Now is the time to make or remove from storage your large custom-made cages that will actually handle healthy, well-grown indeterminate tomato plants that have grown to eight, nine, or even 10 feet high.

Try making strong, tall tomato cages yourself. These will last for a decade or more. You can make them out of concrete-reinforcing wire or hog fencing panels. The reinforcing wire is available at lumber yards. You’ll be calling around to find out if they carry “seven-foot-tall concrete reinforcing wire.” It’s best not to compromise and get the five-foot-tall concrete-reinforcing wire, which is more easily acquired. Your local home improvement store will likely not have the seven-foot-tall wire, so find out which lumber yard near you has the stuff you need.

Now that you’ve identified where to buy the seven-foot wire, you’ll be getting it either cut by the lumber yard or you’ll be buying the whole roll. Each roll is 100 feet long and can make about 18 cages per roll. Use small bolt cutters to cut the wire; anything less beefy may be too taxing for your hands. Roll out the roll partially on a level surface and cut at the twelfth opening. Each opening is 6 inches squared, so you’ll be cutting panels that are seven feet high by six feet wide. The panels will naturally curl, remembering their roll shape. To put them together, curl the two long ends till they meet; then, using heavy leather gloves, bend the cut end over its matching non-cut end so that you end up with a cylinder.

There’s no need to cut off the bottom ring. You might be tempted to do so because then you can poke the lower six inches into the soil—don’t do it. That cut-off six inches is not enough to hold the tomato cage upright, laden with pounds of tomatoes and foliage, during a good wind. You’ll still need to add a piece of rebar next to each cage. So best to leave the lower ring in place and use that left-on six inches of height for your plant.

Rebar is also easily acquired at good hardware stores or lumber yards. A ⅜-inch-thick piece works just fine. Rebar comes in either 10-foot or 20-foot lengths. Have the lumberyard cut your lengths into five-foot pieces. Use one five-foot piece per tomato cage. Pound it into the ground right next to the cage using a small handheld (not long-handled) sledge hammer. Get two feet of the rebar into the ground, with three feet sticking up out of the ground right next to the tomato cage. Then attach the rebar to the cage in several places: low, medium, and at the max height of three feet.

Each tomato gets one cage. You can pop the large concrete-reinforcing cylinder wire cage right over the top of the small conical wire cage or the bamboo stake. The tomato will grow around its first cage and be quite happy in the big cage. The caveat here—and another good reason you need to know the difference between indeterminate and determinate tomatoes—is that you need not use a seven-foot-tall cage for the latter. You should still try to get a beefier cage on your determinates. You can do that by cutting your seven-foot-tall cages in half and giving each of your determinates a three-and-a-half-foot-tall cage around their smaller, wimpier cage. Even a well-grown determinate can topple a small conical wire cage.

As your tomato grows into the cage, push in any branches that start to elongate out of the interior. Branches are characterized by tiny little leaves at their tips. You want to continuously push these into the cylinder so that the branches grow up into the cage rather than out of the cage.

Continued maintenance: Spraying and bug checking

Keep up your weekly regime of worm casting tea and aspirin spray. Also, continually check for bugs using your jeweler’s loupe. Remove a couple of leaves in different locations on each plant and carefully inspect them for bugs through your 20x jeweler’s loupe placed against your eye. Any pesky bugs should be dealt with immediately so they don’t get out of hand; aphids, thrips, mites, and psyllids all can do considerable damage and can even kill your plants. So don’t forget about these two important maintenance items.

 

Resources and Documents
  • April
    World Tomato Society
  • May
    World Tomato Society

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